Left atrial dysfunction: the next key target in heart failure with preserved ejection fraction

Abstract

Left atrial (LA) remodelling and dysfunction are common in patients with heart failure (HF) with preserved ejection fraction (HFpEF).1–4 The distending pressure of the left atrium is principally determined by left ventricular (LV) filling pressure during diastole, and therefore LA remodelling has been considered to be a secondary consequence of LV diastolic dysfunction. However, recent data have shown that LA dysfunction, rather than simply remodelling, may be more than a bystander, but rather an important player in the pathophysiology of HFpEF. Recent studies have shown that LA dysfunction is associated with worse symptoms, more severe pulmonary vascular disease, greater right ventricular (RV) dysfunction, depressed exercise capacity, and increased mortality in HFpEF.1–6 Left atrial function may be assessed by conventional two-dimensional and Doppler echocardiography, but recent studies have shown potentially greater utility of LA deformation analysis using speckle-tracking echocardiography.2–7 Abnormalities in LA mechanics are correlated with resting haemodynamics and clinical status, but it is unknown whether deranged LA mechanics can help identify patients with more profound haemodynamic responses to exercise in HFpEF. In this issue of the Journal, Telles et al.8 present intriguing data that shed new light on the contribution of LA mechanics to abnormal exercise haemodynamics in patients with HFpEF. The investigators prospectively examined 71 subjects with ejection fraction ≥ 50% referred for exercise right heart catheterization because of exertional dyspnoea. Participants were diagnosed with HFpEF [pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest and/or ≥ 25 mmHg with exercise) or non-cardiac dyspnoea (NCD) (PCWP < 15 mmHg at rest and < 25 mmHg with exercise) according to contemporary standards.9 Two-dimensional echocardiography was performed to evaluate resting LA mechanical properties just prior to the invasive measurements. Phases of LA